Alleged violence happened in April involving five third-grade students is making unprecedented development, triggering a public uproar against people with power and money.

The flash point of the incident was two out of four students who beat their classmate were the children of wealthy and powerful families ― one the son of Yoon Son-ha, a famous actress, and another a grandson of Park Sam-koo, chairman of Kumho Asiana Group and the fact that they got away with getting disciplinary measures from the school.

All four are students of Soongeui Elementary School in Seoul, a prestigious school in Seoul, and they were on a school trip when the incident happened.

The school's investigative committee found the four students beat one student with plastic baseball bats and wooden sticks. The victim was covered with a thin blanket. The victim claimed the four students had forced him to drink a bottle of body cleanser when he reached out for water at night.

The school committee closed the case concluding it as a mere prank going wild and didn't hold anyone responsible for it.

However, the victim student was diagnosed with rhabdomyolysis, a condition of skeleton muscle breakdown, and post traumatic stress disorder, and that got the victim's parent to contact SBS, a local broadcast company.

"I concluded that the incident could not be resolved within the school boundary," the 44-year-old mother told the Chosun Ilbo on Sunday. "My son's teacher told me over the phone that it was no more than a prank which has gone out of the control." The mother also accused the school of acting for the interest of the attackers.

The television coverage on June 16 prompted an influx of public outcry against the actress and rich people for days to follow. The Seoul Metropolitan Office of Education started an investigation into the incident on Monday in response.

It also pushed actress mother Yoon to come forward to make an apology for the second time on Monday. "I am sorry for what happened," Yoon said on Monday. Her first apology last week drew backlash for its inadequacy.